PTFE-containing polymers are used as anti-dripping additives in the manufacture of flame retardant thermoplastics. To improve the handling and the compatibility of PTFE with other polymeric matrixes, the anti-dripping additives are created by an aqueous emulsion polymerization processing which unsaturated SAN monomers are added to a fluoropolymer (e.g., PTFE) dispersion to produce a partially SAN-encapsulated PTFE (TSAN) polymer. The encapsulation of PTFE as a core particle with SAN as a shell to form the resulting TSAN composite polymer has at least two benefits: it minimizes the premature fibrillation of the PTFE particles during the coagulation process used to recover TSAN latex and the resulting powdery TSAN latex has improved flowability.